Tennis ball pressurizer to maintain the bounciness of the balls.
https://diqn32j8nouaz.cloudfront.net...r_fullsize.jpg
Previously:
https://www.homemadetools.net/forum/...332#post142272
https://www.homemadetools.net/forum/...759#post183048
https://www.homemadetools.net/forum/...083#post157342
